/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.tomcat.util.digester;

import org.xml.sax.Attributes;

/**
 * Concrete implementations of this class implement actions to be taken when
 * a corresponding nested pattern of XML elements has been matched.
 */

public abstract class Rule {


	// ----------------------------------------------------------- Constructors

	/**
	 * The Digester with which this Rule is associated.
	 */
	protected Digester digester = null;


	// ----------------------------------------------------- Instance Variables
	/**
	 * The namespace URI for which this Rule is relevant, if any.
	 */
	protected String namespaceURI = null;

	/**
	 * <p>Base constructor.
	 * Now the digester will be set when the rule is added.</p>
	 */
	public Rule() {
	}


	// ------------------------------------------------------------- Properties

	/**
	 * Return the Digester with which this Rule is associated.
	 */
	public Digester getDigester() {

		return (this.digester);

	}

	/**
	 * Set the <code>Digester</code> with which this <code>Rule</code> is associated.
	 */
	public void setDigester(Digester digester) {

		this.digester = digester;

	}

	/**
	 * Return the namespace URI for which this Rule is relevant, if any.
	 */
	public String getNamespaceURI() {

		return (this.namespaceURI);

	}

	/**
	 * Set the namespace URI for which this Rule is relevant, if any.
	 *
	 * @param namespaceURI Namespace URI for which this Rule is relevant,
	 *                     or <code>null</code> to match independent of namespace.
	 */
	public void setNamespaceURI(String namespaceURI) {

		this.namespaceURI = namespaceURI;

	}


	// --------------------------------------------------------- Public Methods

	/**
	 * This method is called when the beginning of a matching XML element
	 * is encountered.
	 *
	 * @param attributes The attribute list of this element
	 * @deprecated Use the {@link #begin(String, String, Attributes) begin}
	 * method with <code>namespace</code> and <code>name</code>
	 * parameters instead.
	 */
	@Deprecated
	public void begin(Attributes attributes) throws Exception {
		// The default implementation does nothing
	}

	/**
	 * This method is called when the beginning of a matching XML element
	 * is encountered. The default implementation delegates to the deprecated
	 * method {@link #begin(Attributes) begin} without the
	 * <code>namespace</code> and <code>name</code> parameters, to retain
	 * backwards compatibility.
	 *
	 * @param namespace  the namespace URI of the matching element, or an
	 *                   empty string if the parser is not namespace aware or the element has
	 *                   no namespace
	 * @param name       the local name if the parser is namespace aware, or just
	 *                   the element name otherwise
	 * @param attributes The attribute list of this element
	 * @since Digester 1.4
	 */
	public void begin(String namespace, String name, Attributes attributes)
			throws Exception {

		begin(attributes);

	}

	/**
	 * This method is called when the body of a matching XML element
	 * is encountered.  If the element has no body, this method is
	 * not called at all.
	 *
	 * @param text The text of the body of this element
	 * @deprecated Use the {@link #body(String, String, String) body} method
	 * with <code>namespace</code> and <code>name</code> parameters
	 * instead.
	 */
	@Deprecated
	public void body(String text) throws Exception {
		// The default implementation does nothing
	}

	/**
	 * This method is called when the body of a matching XML element is
	 * encountered.  If the element has no body, this method is not called at
	 * all. The default implementation delegates to the deprecated method
	 * {@link #body(String) body} without the <code>namespace</code> and
	 * <code>name</code> parameters, to retain backwards compatibility.
	 *
	 * @param namespace the namespace URI of the matching element, or an
	 *                  empty string if the parser is not namespace aware or the element has
	 *                  no namespace
	 * @param name      the local name if the parser is namespace aware, or just
	 *                  the element name otherwise
	 * @param text      The text of the body of this element
	 * @since Digester 1.4
	 */
	public void body(String namespace, String name, String text)
			throws Exception {

		body(text);

	}

	/**
	 * This method is called when the end of a matching XML element
	 * is encountered.
	 *
	 * @deprecated Use the {@link #end(String, String) end} method with
	 * <code>namespace</code> and <code>name</code> parameters instead.
	 */
	@Deprecated
	public void end() throws Exception {
		// The default implementation does nothing
	}

	/**
	 * This method is called when the end of a matching XML element
	 * is encountered. The default implementation delegates to the deprecated
	 * method {@link #end end} without the
	 * <code>namespace</code> and <code>name</code> parameters, to retain
	 * backwards compatibility.
	 *
	 * @param namespace the namespace URI of the matching element, or an
	 *                  empty string if the parser is not namespace aware or the element has
	 *                  no namespace
	 * @param name      the local name if the parser is namespace aware, or just
	 *                  the element name otherwise
	 * @since Digester 1.4
	 */
	public void end(String namespace, String name)
			throws Exception {

		end();

	}

	/**
	 * This method is called after all parsing methods have been
	 * called, to allow Rules to remove temporary data.
	 */
	public void finish() throws Exception {
		// The default implementation does nothing
	}


}
